1. Field of the Invention
The present invention relates to a touch sensor capable of polarizing a light beam for being employed in a LCD (Liquid Crystal Display) panel or monitor.
2. Background Description
In the present technologies for concerning the convenience and friendship, the user interface is developed to implement ordinary user habits. Thus, users may manipulate the technology products via an interactive human interface, rather than learning lots knowledge and computer instructions, such for computers, home appliances, guiding systems (G.P.S. or others) and personal digital assistance (PDA). The screens of high technology products are able to be clicked in order to input the instructions directly via screens, so-called touch screens. Thus, the user friendly interface is enhanced from ordinary input devices such as mouses or keyboards.
The touch screens as aforementioned, as shown in FIG. 1, includes a glass substrate 10, a first conductive layer 11, a first insulation layer 12, a first electrode layer 13, an isolation layer 14, a second electrode layer 15, a second insulation layer 16, a second insulation layer 17 and a film 18. The first conductive layer 11 and the second conductive layer 17 are conductive materials, for example Indium Tin Oxide (ITO). The first conducted layer 11 is sputtered to the glass substrate 10. The second conductive layer 17 is also sputtered to the film 18. In this case, both the glass substrate 10 and the film 18 are conductive. After that, the first insulation layer 12 and the second insulation layer 16 are printed to the glass substrate 10 and the film 18 respectively. The first conductive layer 12 and the second conductive layer 16 are designated to spread equipotential voltage filed over the conductive layers. The first electrode layer 13 and the second electrode layer 15 are made by conductive material, such as silver paste. The first electrode layer 13 and the second electrode layer 15 are printed to the first conductive layer 11 and the second conductive layer 17 respectively. A first electrode 131 and a second electrode 132 of the first electrode layer 13 are positioned in parallel. A third electrode 151 and a fourth electrode 152 of the second electrode 15 are also positioned in parallel. The electrode leads 133, 134, 153 and 154 are connected to the first electrode 131, the second electrode 132, the third electrode 153 and the fourth electrode 154 respectively for propagating signals. Once the isolation layer 14 is printed on the first conductive layer 11, a touch screen is completed after combining the glass substrate and the film by an adhesive material.
Please refer to FIG. 2A, the figures shows the cross section along line A-Axe2x80x2, especially under the condition that the user does not press down the film or the user does not click on the screen. There is an isolation layer between the first conductive layer 11 and the second conductive layer 17. The isolation layer 14 contains plurality of spacers 140 in order to prevent the contacts between the first conductive layer 11 and the second conductive layer 17. If the first conductive layer 11 and the second conductive layer 17 are not contacted, there will be no signal generated and outputted. Further in view of FIG. 2B, if the user presses down or clicks on the film 18 by user""s finger 19, the film 18 will be bent. Thus, the second conductive layer 17 is bent to contact the first conductive layer 11. Since the first electrode 131 is provided a five voltage (5V) via the electrode lead 133 and the second electrode 132 is provided a zero voltage (0V) via the electrode lead 134, there is voltage gap of five voltage (5V) between the first electrode 131 and the second electrode 132. In this case, a general and equivalent equipotential filed from 0V to 5V is generated. If the second conductive layer 17 is bent to contact the first conductive layer 11, the coordinates of the contact point 21 will be recognized by sampling out the voltage signal. The voltage presents the one axis position of the coordinate of the contact point 21, such as the position along X-axis. After a predetermined time shift, an equipotential filed is generated between the third electrode 151 and the fourth electrode 152. By sampling out the voltage signal of the contact point, the position of the coordinate of the contact point is acquired along the Y-axis as shown in FIG. 1. By switching the two equipotential fields on the first conductive layer 13 and the second conductive layer 15, the coordinates of the movement of the finger on the film 18 will be acquired. Accordingly, the touch sensor 1 is required to be integrated with a display (usually a liquid crystal display). In this case, the user may see the content of the display in order to touch the touch sensor to input the instruction.
In an ordinary liquid crystal display, there is implemented a polarizer for polarizing a light beam with a specific polarity. FIG. 3A shows the structure of the polarizer 2. The polarizer 2 comprises a polarizing layer 20, a first protection layer 22 and a second protection layer 24. The polarizing layer 20 is a PVA (Poly Vinyl Alcohol). The characteristic of the PVA is to allow a light beam with a specific polarity to pass. The first protection layer 22 is positioned in the upper side of the polarizing layer 20, made by the material of PET or other insulating materials. The second protection layer 24 is positioned below the polarizing layer 20, made by the material of PET or other insulating materials for protecting the polarizing layer 20. Moreover, the first protection layer 22 and the second protection layer 24 are also for preventing any bending causes to the polarizing layer 20.
Regarding the cost of the manufactures, Minoura et al. have disclosed a way to combine the touch sensor 1 and polarizer 2 together. See U.S. Pat. No. 6,108,064. Minoura et al. taught to integrate the touch sensor 1 and the polarizer 2 by adhesive. As shown in FIG. 3B, the touch sensor 1 sticks to the polarizer 2 by adhesive. Thus, the liquid crystal display (not shown in FIG. 3B) employing the polarizer 2 is capable of touch features.
However, this kind of manufacturing processes require lots alignment procedures. Further, to paste the adhesive over either the touch sensor 1 or the polarizer 2 will easily leave some adhesive on the touch sensor 1 or the polarizer 2, which causes lots rejected products along with other defected issues. In this case, the present invention provides an integrated touch sensor or called an integrated polarizer for reducing the aforementioned problems.
It is therefore an object of the present invention to provide a polarizing device integrated with a touch sensor. So that the polarizing device is capable of touch features.
It is another object of the present invention to provide a low-cost device to be implemented to the liquid crystal display.